Section 1 Evolution of Behavior - Jourdanton ISD · • Lesson Plan • Directed Reading ... in response to a stimulus. ... no variation in what she does,

OverviewBefore beginning this sectionreview with your students theobjectives listed in the StudentEdition. In this lesson, students willidentify animal behaviors. Theyalso will describe the roles that natural selection and genes play indetermining behavior. Finally, theywill be able to recognize thatbehavior is influenced by the environment and learning as wellas genetics.

Ask students to write down anexample of an animal behavior.Ask them to write about an adap-tive advantage that the behaviormight confer. (For example, akitten’s meow is adaptive because itresults in the kitten’s mother focusingher attention on the kitten and pro-viding him food or meeting someother need.)

Discussion/QuestionAsk student volunteers to describeat least one thing they have taughttheir pets. For example, did stu-dents house-train their dogs byusing a punishment (such as a swatwith a newspaper) after an “acci-dent,” or did they use a reward(such as a dog treat or praise) ifthe dog urinated while outdoors?Ask students which method (posi-tive or negative) they believe ismore effective, and why.

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824 Chapter 36 • Animal Behavior

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Section 1 Evolution of Behavior

What Is Behavior?A squirrel buries a nut; a hungry baby cries. A frog jumps into apond to avoid a predator, and a driver applies the brakes whenapproaching a red traffic light. These are all examples of behavior.A is an action or series of actions performed by an animalin response to a stimulus. The stimulus might be something in theenvironment, such as a sound, a smell, a color, or another individ-ual. The stimulus can also be related to the internal state of the ani-mal, such as being hungry or cold. For example, when under threat,the lizard shown in Figure 1 flares out the folds of skin around itshead. This gives it a threatening appearance, which tells potentialenemies to stay away.

Scientists studying behavior investigate two kinds of questions—“how” questions and “why” questions. “How” questions are abouthow a behavior is triggered, controlled, and performed. Forinstance, consider the squirrel, also shown in Figure 1. “How” ques-tions about squirrel behavior might include “How does a squirrelselect which nuts to bury?” “How does it choose where to bury thenut?” and “How does it remember where the nut is?”

However, answering “how” questions provides only a partialunderstanding of a behavior. Scientists also try to answer “why”questions, such as “Why do squirrels bury nuts?” “Why” questionsconcern the reasons a behavior exists and are really questionsabout the evolution of behavior. A study of animal behavior maytherefore seek to identify the benefits of a particular behavior.

behavior

Objectives● Distinguish between “how”

and “why” questions aboutbehavior.

● Describe how natural selec-tion shapes behavior.

● Compare innate and learnedbehaviors.

● Summarize how behavior isinfluenced by both heredityand learning.

Key Terms

behaviorinnate behaviorfixed action patternbehavior

learningconditioningreasoningimprinting

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Figure 1 Animal behavior.This Australian frilled lizard and gray squirrel are engagingin behaviors typical of theirspecies.

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Teaching TipRecognizing Relationships Pointout to students that scientists seekto answer “how” and “why” ques-tions in all areas of biology. Forexample, geneticists have learnedmuch about how meiosis occurs —how the chromosomes line upand separate and how cytokinesisoccurs. But they are also interestedin why meiosis occurs and whatbenefits it brings to the organism.Ask students to come up with some“how” and “why” questions aboutsubjects they studied in previouschapters. Then ask students toanswer their questions.

Interactive Reading AssignChapter 36 of the Holt BiologyGuided Audio CD Program to helpstudents achieve greater success inreading the chapter.

Group Activity Animal Trainer Invite a dog obedience trainer to visit your classand to discuss the most effectivemethods he or she uses to traindogs. Ask the trainer to share hisor her favorite stories of incidentsthat have occurred during training.Beforehand, have each student for-mulate five questions to ask thetrainer. Be sure to ask for thetrainer’s opinion on negative reinforcement versus positive reinforcement. If school rulesallow, have the trainer bring a dogand demonstrate training skills inthe classroom. InterpersonalBio 3D

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Chapter 36 • Animal Behavior 825

CulturalAwarenessCulturalAwareness

Australian Aborigines To the earlyEuropean colonists of Australia, the absenceof aboriginal technology indicated that theywere a very primitive people. The Aboriginescould produce only a limited variety of toolsbecause they did not know how to mine,smelt, or work metal. They had to rely onhunting and gathering because they did notpractice agriculture. Most groups did notwear clothes, even in winter. The largest“structures” they created were piles of

discarded shells. However, as the Europeanssoon learned, the Aborigines compensatedfor their technological “deficiencies” with adeep and detailed knowledge of their envi-ronment, which allowed them to survive inareas where European explorers and settlersperished. In particular, the Aborigines wereexperts on the behavior of animals, and theyused this knowledge to capture game and tofind water in dry areas.

English Language Learners

Natural Selection and Behavior Recall that evolution by natural selection is aprocess by which populations change inresponse to their environment. Natural selec-tion favors traits that improve the likelihoodthat an individual will survive to reproduce.Over time, traits that provide a reproductiveadvantage become more common. Traits thatdo not provide an advantage become less com-mon and may disappear.

An understanding of natural selection canhelp answer a “why” question. A good exampleof this is seen in East African lions, which livein small groups called prides. Each pride con-tains several adult females, several young lions(called cubs), and one or more adult males. Theadult males father all the cubs and defend thepride against other males. But a male or groupof males usually can control a pride for only acouple of years. Then they are forced out byyounger males who take over the pride. Whenthis happens, the new males often kill all theyoung cubs in the pride, as shown in Figure 2.In contrast, male lions are usually quite tolerantof their own offspring, also shown in Figure 2.

To understand this behavior, we need to understand how the newmales would benefit from it. The new males will control the pridefor only a few years, so they have a very short time in which toreproduce. But female lions with cubs will not breed until theircubs are grown, which may take more than two years. If a female’scubs die, however, she will mate again almost immediately.

Why do the new males kill the cubs? One hypothesis suggeststhat the new males will father more cubs as a result of this behav-ior. Note, however, that this does not suggest that male lions areaware that they are killing the offspring of other males, or that theyunderstand how they will benefit from this behavior.

Individual SelectionYou may have heard it said that a trait or behavior ensures thesurvival of the species. This once popular belief is now consideredfalse. Most scientists now agree that natural selection favors traitsthat contribute to the survival and reproduction of individuals, notspecies. The actions of male lions support this idea. Cub-killingincreases the already high death rate among cubs and actuallyreduces the likelihood that the species will survive. Because naturalselection favors traits that benefit individuals, the male lionsusually will behave in ways that are favorable for them, not forthe pride as a whole.

Figure 2 Behavior in malelions. After taking over apride, a male lion often kills the young cubs in the pride.However, the males are usuallytolerant of their own cubs.

www.scilinks.orgTopic: Animal BehaviorKeyword: HX4008

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Teaching TipInnate Behaviors Ask students toname several innate behaviors. (forexample, suckling, eating, and drink-ing) Ask them why they think it isimportant for these behaviors to beinstinctive rather than learned. Nextask them to come up with a hypo-thetical behavior that would be adisadvantage to an animal. (forexample, a bird refusing to fly whenit is capable of doing so) Ask: Whatwould most likely happen to thisbird? Would its genes be passed onto the next generation?

Using the Figure Have students examine the hybridlovebird in Figure 4. Ask: Whatnesting behaviors does this birdexhibit that are similar to those ofthe Fischer’s lovebird? (It carriesnesting materials in its beak.) Whatnesting behaviors are like those ofthe peach-faced lovebird? (It placesnesting materials in its feathers.)What problem does it encounter?(It fails to let go of the nesting mate-rial in its mouth, so the material doesnot stay tucked into its feathers.)

Visual

Activity Ask students how biologists knowthat the orb spider does not learnto build its web. Ask each studentto design an experiment that woulddemonstrate that web building bythe orb spider is innate. LogicalTAKS 1 Bio/IPC 2A

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Bower Birds The male bower bird has a fas-cinating and complex courting behavior.Instead of relying on its plumage or song toattract a mate, the bower bird constructs anelaborate structure called a bower using leaves,twigs, and other items it finds on the ground.The bower bird goes one step further and dec-orates the bower with colorful items rangingfrom feathers, pebbles, berries and shells tocoins, spoons, and even pieces of aluminumfoil. However, the bowers aren't nests for rais-ing chicks; they are strictly for attracting

females for mating. When a female arrives andinspects the bower, the male struts in front ofthe bower and sings. Mating takes place afterthe female deems the bower acceptable andenters it. The female then leaves the bower andbuilds a nest nearby. There are 17 species of bower birds inAustralia and New Guinea, each with its ownstyle of bower. For example, the satin bowerbird paints the walls of its bower with chewedberries or charcoal. Others use moss to createa lawn. TAKS 2 Bio 6D


Genetically Influenced BehaviorFrom years of observation and experimentation, biologists havelearned that many kinds of animal behaviors are influenced bygenes. Genetically programmed behavior is often called

, or more commonly, instinct. The orb spider, shown inFigure 3, builds her web the same way every time. There is little orno variation in what she does, and her female offspring will buildtheir webs in the same manner without being taught. This type ofinnate behavior is called because theaction always occurs the same way.

Demonstrating the Genetic Basis of BehaviorNest building is an innate behavior exhibited by most birds, includingAfrican lovebirds, shown in Figure 4. These small parrots constructtheir nests from materials that they collect and carry back to the nestsite. One species of lovebird, Fischer’s lovebird, carries a single longstrip of nesting material in its beak. A second, closely related species,the peach-faced lovebird, carries several short strips of nesting mate-rial tucked into the feathers near its tail.

Evidence that these behaviors have a genetic basis comes fromstudies in which the two types of lovebirds were interbred. Asshown in Figure 4, the resulting hybrid birds showed nestingbehaviors that resembled those of both parents. They chosemedium-length strips of nesting material and tried to place thestrips in the feathers near their tail. But the hybrid birds were rarelysuccessful because they did not let go of the strips after placingthem in their feathers. Eventually, some of the hybrid birds learnedto carry the nesting material in their beak.

fixed action pattern behavior

behaviorinnate

The hybrid offspring of two lovebird species show nest-building behaviorssimilar to those of both parents.

Figure 4 Nest building behavior

Figure 3 Fixed actionpattern behavior. Like all web-building spiders, the orb spideris genetically predisposed tobuild her web the same wayeach time.

Fischer’s lovebirdscarry nesting materialin their beak.

Peach-faced lovebirdscarry nesting materialtucked into the feathersnear their tail.

Their hybrid offspring tuck nesting material into their feathers but never let go of it. As a result, the nesting material does not stay in place.

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Trends in PsychologyThink Positively In a clinical study,researchers found that attitude and mindsetreally can affect a person’s overall health.Researchers Martin Seligman and GregoryBuchanan, both of the University ofPennsylvania, studied the behavior of universityfreshman, including coping skills and levels ofdepression experienced by the students.Incoming freshman first took a survey to identify their general attitudes and ability tocope. Students who were identified as themost pessimistic by this survey participated in

the study. The study included a workshopgroup and control group. In the workshopgroup, students learned how to dispute theirown negative thinking as well as social skillsfor averting depression.Results of the study show that after an 18-month follow-up, 22 percent of the stu-dents who participated in the workshop experienced moderate or severe depression,versus 32 percent from the control group.Bio/IPC 3C

Teaching TipPavlov’s Experiments Pavlov’sdogs initially would salivate onlyin response to the meat powderstimulus. Salivation is an uncondi-tioned response, meaning it occursautomatically and does not have tobe learned. Remind students thatthey show a similar behavior whenthey sense food. Ask students tospeculate about what the functionof this response might be.(Salivation prepares the mouth toreceive food by lubricating themouth and increasing the concentra-tion of a digestive enzyme found insaliva.) Intrapersonal

Group Activity Learning in Pets Divide the classinto two-person teams, and haveeach team design an experiment totest the ability of a pet to learn anew behavior. Suggest some possi-bilities, such as teaching a dog anew behavior or having a mouseperform some sort of activity toobtain food. Encourage students totest different conditions on theirown time to determine if onemethod is more successful. Forexample, a dog that performs acertain behavioral response can berewarded with food. In a secondconditioning experiment, the samedog can be rewarded with pettingwhen it exhibits the desiredresponse. Students can then corre-late the learning time with the typeof reward. If students plan to carryout their experiments, be sure theytreat all animals in a humane man-ner. Guidelines for working withvertebrates are available from theNational Association of BiologyTeachers. Have students write areport describing their procedureand the results of their experiments.

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TT Nest Building Behavior

Learning and Behavior Behaviors are influenced by genes, but to what degree can behaviorsbe modified by experience? The development of behaviors throughexperience is called . Learning can influence the expressionof innate behavior and the expression of behaviors that are notinnate. One simple kind of learning is habituation. In habituation, ananimal learns to ignore a frequent, harmless stimulus. For example,birds may at first stay away from a garden that has a new scarecrow.But if the position of the scarecrow is not changed on a regular basis,the birds learn to ignore it and go into the garden unafraid.

Classical Conditioning A more complex type of learning is , or learning byassociation. One of the most famous studies of conditioning wasRussian psychologist Ivan Pavlov’s work with dogs, carried out inthe late 1890s and early 1900s. When Pavlov presented meat powder(a stimulus) to a hungry dog, the dog salivated—an innate responseto food. At the same time the dog received the meat powder, Pavlovalso presented the dog with a second, unrelated stimulus—a ringing bell. After repeated trials, the dog learned to associate the ringingbell with the meat powder and would salivate in response to the bellalone. The dog became conditioned to associate the ringing of thebell with a reward (meat powder). This type of conditioning, inwhich an animal comes to associate an unrelated response with astimulus, is called classical conditioning.

Trial-and-Error Learning Animals also learn by trial-and-error thatperforming a certain action will result in areward or a punishment. For example, adog may learn to avoid a particular catafter being scratched on the nose once ortwice. When trial-and-error learningoccurs under highly controlled condi-tions, it is called operant conditioning.

Operant conditioning was demonstratedin another famous set of experiments con-ducted by the American psychologist B. F.Skinner. Skinner studied learning in ratsby placing them in a “Skinner box,” illus-trated in Figure 5. Once inside, the ratwould explore the box. Occasionally, itwould accidentally press a lever, and a pel-let of food would appear. At first, the rat would ignore the lever andcontinue to move about, but it soon learned to press the lever toobtain food. This sort of trial-and-error learning is of major impor-tance to most vertebrates, and it influences many behaviors essentialto survival, such as searching for food.

conditioning

learning

Figure 5 Skinner box.When placed in a Skinner box,this rat learned by trial-and-error to push a lever to receivea reward of food.

Recognizing DifferencesTo understand the difference between classical and operant conditioning, think abouthow the behavior is learned.In classical conditioning, thestimulus has no relationshipto an activity. In operantconditioning, there is adirect relationship.

www.scilinks.orgTopic: ConditioningKeyword: HX4050

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RecognizingLearned BehaviorSkills Acquired Observing, collectingdata, analyzing data,evaluating

Teacher’s Notes Have students work in smallgroups. Before they begin, haveeach group formulate a hypoth-esis about what the sow bugswill do.

Answers to Analysis1. Answers will vary depending

on sow bug behavior.2. Answers will vary depending

on sow bug behavior.3. Answers will vary, but make

sure that students’ answers aresupported by evidence.

4. If the sow bugs show a prefer-ence for the wet paper toweland if no other factors influ-ence the direction they turn,the bugs should exhibit ran-dom turning behavior if drypaper toweling is used.

SOCIOLOGYSOCIOLOGYCONNECTIONCONNECTION

• 85% whose mother had completed vocational education or some college,

• 91% whose mother had a college degree,and

• 93% whose mother had a graduate/professional degree or training.

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The National Household Education Surveyfound the following for 3- to 5-year-olds notyet enrolled in kindergarten in 1999:

• 61% whose mother's highest education wasless than high school were read to three ormore times in the past week by a familymember, compared with

• 76% whose mother had a high schooldiploma or equivalent,

Reasoning The ability to analyze a problem and think of a possible solution iscalled . Reasoning involves using experience to developan insight into how to solve a new problem. The dog shown in Figure 6 cannot think of a solution to the situation it is in. Humansand some other primates show the ability to reason. For example, inone experiment a chimpanzee was placed in a room with someboxes and a banana hung high overhead. Although it had not beenin a similar situation, the chimpanzee stacked up the boxes to reachthe banana, a behavior that required reasoning.

There has been much research anddebate over the ability of other animals,such as dolphins, some parrots, andeven octopuses, to reason. So far, thereis no clear evidence that other animalscan reason. Many animals can, how-ever, learn complex tasks. Some birdsliving in cities have learned to removethe foil covering from bottles of non-homogenized milk to reach the creamat the top. Japanese snow monkeyshave learned to float grain on water toseparate the grain from sand.

reasoning

Recognizing Learned Behavior Sow bugs must keep moist to survive. Follow theprocedure below to see if sow bugs can learn to find moisture.

Materials

small wads of paper towel (one moist and one dry), T-maze made of two 6 cm (about 2.25 in.) pieces of 1.25 cm (0.5 in.) clear vinyl tubing, sow bug, blunt probe

Procedure

1. Place the moist paper wad inthe open end of the left sideof the T, and place the drypaper wad on the right side.

2. Place the sow bug at thebottom of the T. If it does notstart to crawl, gently prod itwith a blunt probe.

3. Observe what the sow bugdoes when it reaches the Tsection. Retrieve the sow bug

and perform as many trials astime allows.

4. Keep a record of the resultsof each trial.

5. Using the same sow bug,repeat this procedure forthree days.

Analysis

1. Summarize your sow bug’sbehavior, in writing or on a graph.

2. Describe any trend inbehavior that you observed.

3. Determine if your sow bugmodified its behavior throughlearning, using evidence tosupport your answer.

4. Evaluate the value of per-forming a final trial in whichthe T-maze contains two drypaper wads.

Figure 6 An inability toreason. Although the solutionseems obvious to humans,this dog is unable to figure outhow to reach the food.

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Biology/IPC Skills TAKS 1 Bio/IPC 1ADemonstrate safe practices during fieldand laboratory investigations.Activity Ask students to imagine thatthey will be going into the wilderness toobserve animal behavior. Have studentsbrainstorm a list of safety concernsthey may encounter and ways in whichthey can avoid these dangers.

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Answers to Section Review

1. “How” questions are about how a behavior is triggered, controlled, and performed. “Why” questions concern the adaptive value ofa behavior.

2. By killing the cubs, the male lion increases hischances of fathering his own cubs, therebyincreasing the likelihood that his “cub-killing”genes will be passed on.

3. Innate behavior, such as eating, requires noexperience. Learned behavior, such as a dogsalivating in response to a ringing bell, is modi-fied by experience.

4. In imprinting, an animal is genetically pro-grammed to learn something during a critical

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ReteachingHave students select any behaviorthat is described in this section.Ask them to write a list of “why”and “how” questions that a scien-tist could ask about that particularbehavior. (For example: Why does a gosling follow any object shortlyafter hatching? How does this behavior change, if at all, over time?)

Quiz1. A behavior occurs in response to

a ________ . (stimulus)

2.What does the experiment withhybrid lovebirds demonstrate?(It demonstrates that some behav-iors are determined entirely bygenes.)

3. When a young child learns howto build a tower of blocks byrepeating her efforts until shesucceeds, what kind of learningis the child demonstrating? (trial-and-error learning)

AlternativeAssessmentHave students observe the behaviorof a pet or other animal and writea report describing their observa-tions. In their reports, studentsshould describe the behaviors oftheir subject and the context foreach behavior. Students should alsoexplain the possible adaptive valueof each behavior they observe.TAKS 1 Bio/IPC 2B, 2D

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Genetic and Learned Aspects of BehaviorDo genes determine most behaviors, or do animals usually learn howto behave from experience? Over the last century, this topic has beendebated. Some scientists argued that most behaviors are geneticallyprogrammed because different individuals in the same species act inthe same ways. Other scientists claimed that behaviors are shaped byan animal’s experiences. Most biologists who study animal behaviorhave come to think that animal behavior, particularly the complexbehavior of vertebrates, has both genetic and learned components.

ImprintingLearning that can occur only during a specific period early in thelife of an animal and cannot be changed once it occurs is called

. Imprinting is easily observed in young geese and ducks,which have no innate recognition of their mother. Instead, thesebirds are genetically programmed to follow the first moving objectthey see during a short period immediately after they hatch.

There is great survival value to this behavior, as the young mustfollow their mother as she leads them to water, helps them find food,and keeps them out of danger. However, the young will follow anyobject they see during this period just as they would their mother—including toy wagons, boxes, and balloons. Once the young birdsimprint on an object, they prefer to follow it, even when given theopportunity to follow a member of their own species.

Konrad Lorenz, a Nobel Prize-winning pioneer in the study of ani-mal behavior, observed imprinting when he raised a group of newlyhatched goslings (young geese) by hand and found that they imprintedon him. Figure 7 shows Konrad Lorenz leading his “family” ofgoslings. The goslings ability to imprint on an object during a sensitiveperiod is not a learned behavior; it is programmed into their genes.However, the process of imprinting is a form of learned behavior. Thuslearning determines the final shape of this genetically based behavior.

imprinting

www.scilinks.orgTopic: ImprintingKeyword: HX4104

Figure 7 Imprinting. Thesegoslings imprinted on KonradLorenz and followed himaround just as if he weretheir mother.

Section 1 Review

Describe the difference between “how” and “why”questions in regard to animal behavior. 7B

Summarize how cub killing by male lionssupports the hypothesis that natural selectionshapes behavior. 7B

Distinguish between and give an example ofinnate and learned behavior. 11B

Analyze the behaviors involved in imprinting.11B

Critical Thinking Forming ReasonedOpinions A friend is teaching his dog a newtrick in which it is rewarded each time the trick isperformed correctly. The friend says his methodis called classical conditioning. Evaluate yourfriend’s use of this term. 7B

When an Australian frilledlizard flares the folds of skin around its head inresponse to a threat, the lizard exhibits A imprinting C classical conditioningB trial-and-error learning D an innate behavior

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period early in its life. Once learned, theimprinted information cannot be changed.

5. The friend’s usage is incorrect. In classical con-ditioning, the stimulus has no relationship tothe activity. This is a case of trial-and-errorlearning.

6. A. Incorrect. Imprinting involveslearning during a specific period early in life. B. Incorrect. Trial-and-error learning is a learnedbehavior that involves repeated attempts toachieve a correct behavior. C. Incorrect. Classicalconditioning involves learning to associate astimulus with an unrelated response. D. Correct.

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OverviewBefore beginning this sectionreview with your students theobjectives listed in the StudentEdition. Students will be able todescribe six different categories of animal behavior and some of the influences that shape thesebehaviors, both genetic andlearned. Students will develop anunderstanding of the nature ofcommunication between animalsand what influences communica-tion. Finally, students will explainmate selection in animals.

Ask students to write a sentencedescribing the eating behavior of adog and another sentence describ-ing the eating behavior of a cat.Ask them finally to write a sentencethat characterizes the differences ineating behaviors of dogs and cats.(Dogs are generalists and eat mostany food, while cats are specialistsand eat primarily meat.)

Discussion/QuestionHave the class write the six cate-gories of behavior from Figure 9on the board. Then, have studentswrite an example for each type ofbehavior below each of the sixcategories. Allow healthy disagree-ment among students as you lead adiscussion of the characteristics ofeach category.

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TT BellringerTT Animal Behavior

Section 2 Types of Behavior

Categories of Animal BehaviorAs you sit on a park bench, a pigeon approaches, and you soon real-ize that it expects food. You toss out a bit of your sandwich and thepigeon eats it, immediately looking up for more. This urban pigeonhas been conditioned to seek food from people. Has its humansupplier been conditioned too?

Behavior is an animal’s most immediate way of dealing with itsenvironment. Because the environment is complex and can changerapidly, most animals have many different kinds of behavior, eachsuited to a particular situation. For instance, a squirrel mayperform one kind of behavior when it finds a nut on the ground—it digs a hole. It performs a completely different behavior when asnake approaches—it runs for shelter—because digging a holewould not help it escape from the snake.

Like the squirrel, the musk oxen of the Arctic display manydifferent types of behavior, some of them cooperative. When preda-tors, usually wolves, appear, the adult musk oxen form a defensivecircle around their young, as shown in Figure 8. The tight circle andthe danger of injury from the adult’s horns and hooves usuallyprevent a successful attack. While musk oxen can run, running wouldnot protect the herd in the way that their group defense does.

Biologists have classified the behaviors animals perform intoseveral broad categories. Figure 9 shows some of these categoriesand gives an example of each.

Objectives● Discuss six types of animal

behavior.

● Discuss how animals usesignals.

● Summarize how sexualselection can influenceevolution.

Key Terms

sexual selection

Figure 8 Musk oxen.When threatened, adult muskoxen form a defensive circlearound their young.

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Group ActivityAnimal Behavior Copy theGraphic Organizer at the bottomof this page onto the board or anoverhead, but do not copy theentries in parentheses. Have volunteers come up one at a timeand fill in the blanks. Students’answers may vary from the onesgiven. Logical

Teaching TipMigratory Behavior Tell studentsthat migration may bring a bird toa much more favorable environ-ment where resources, such as foodand nesting sites, are available,where predators are rare, or wherethe climate is moderate. Costs ofmigration include the energyrequired to fly long distances andthe possibility of dying during thelong migration.

Reading Organizer Have stu-dents make a table with the following headings: Parental Care,Courtship Behavior, DefensiveBehavior, Foraging Behavior,Migratory Behavior, and TerritorialBehavior. As students read thissection, they should assign eachbehavior mentioned in the text toone of the categories in the table.Inform students that some behaviors will not fit into any ofthe categories, so it will not be possible to classify all the behav-iors described in the section.

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Graphic Organizer

Use this graphic organizer with Group Activity on this page.

Type of behavior Function of behavior Example of behavior(Parental care) Ensuring survival of young (Bird feeds worm to nestling.)

(Courtship behavior) (Attracting a mate) Male frogs croak to attract a mate.

(Defensive behavior) Protection from predators (Hognose snake plays dead.)

(Foraging behavior) (Locating, obtaining, and A raccoon searches along streamsconsuming food) and ponds for rodents.

(Migratory behavior) (Moving to a more suitable Birds fly south for the winter.environment)

Territorial behavior (Protecting a resource for (An aquarium fish forces all otherexclusive use) fish to one end of the tank.)

Influences on BehaviorWhile many of the behaviors illustrated in Figure 9 may seem differ-ent from one another, they all tend to favor survival and reproductivesuccess. To gain a better idea of the nature of animal behavior, let’sexamine one of these behaviors—foraging behavior—in detail.Foraging is finding and getting food.

Animals can be divided into two broad groups based on the rangeof food items each group consumes. Specialists feed primarily orexclusively on one kind of food. Some species of ants, for example, eatonly spider eggs. Generalists, in contrast, consume many differentkinds of food. For example, some insects eat the leaves of a wide vari-ety of plants. Generalists are typically less efficient than specialists at

Figure 9 Animal behavior.Although their methods differ,all animals engage in atleast some of the behaviorsshown below.

Defensive behavior

Protect from predators

When threatened, a hognose snake turns onto its back and plays dead.

Parental care

Ensure survival of young

This robin is feeding an insect to its offspring.

Migratory behavior

Move to a more suitable environmentas seasons change

Monarch butterflies migrate thousandsof kilometers, from the United States tocentral Mexico.

Courtship behavior

Attract a mate

During its breeding season, the malestickleback fish develops a brightcoloring and builds an elaborate nest to attract a female.

Foraging behavior

Locate, obtain, and consume food

A raccoon searches along streams andponds for fish, frogs, crayfish, andsmall rodents. It also hunts for insectsand fruit in woodlands.

Territorial behavior

Protect a resource for exclusive use

Like many wild cats, this youngcheetah claws on trees, leaving a scent that marks its territory.

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feeding on any one type of food. However, generalists have the advan-tage of being able to collect more than one kind of food. Whichapproach to foraging is better? When one kind of food source is plen-tiful, specialists forage more successfully. But when food sources arediverse and no particular one of them is more common, generalistsfind more to eat.

For predators, food typically comes in a variety of sizes. Largerfood items contain more energy. But larger items are harder to cap-ture, and they are usually less abundant.

Foraging thus involves a trade-off between a food’s energy con-tent and its availability. Animals tend to feed on prey that maximizetheir energy intake per unit of foraging time. This approach iscalled optimal foraging. Natural selection has favored the evolutionof foraging behaviors of this sort. Sometimes, however, animals willconsume foods that are low sources of energy. Often this is becausethose foods supply an important nutrient. The location of the foodsource may also allow the consumer to avoid being captured bysome other predator.

www.scilinks.orgTopic: Animal

CommunicationKeyword: HX4009

The Gregarious Lobster

You may think of lobsters asbeing solitary animals, but

at least one species, theCaribbean spiny lobster, Pan-ulirus argus, is gregarious.These lobsters engage in massmigrations during the fall. Whenmigrating, they can be found ingroups of 60 or more individuals.Scientists at Southwest TexasState University in San Marcoshave been investigating thegregarious behavior of spinylobsters and how it is used todefend against predators.

Queues, Rosettes, and PhalanxesDuring the migratory season,spiny lobsters typically movesingle file across open sand ingroups called queues. Whentwo queues meet, they mayjoin to form a longer queue. Eachfollower in a queue uses itsantennae and front legs to main-tain constant contact with the

extended abdomen of the lob-ster ahead. Queuing reducesfluid drag on the followers, justas drafting lowers wind resis-tance on race cars.

Reduced drag probably isn’tthe major benefit that spiny lob-sters receive by forming queues,however. Traveling this way givesthem greater protection againstpredators, such as the trigger-fish. When confronted by apredator, a queue quickly reor-ganizes itself into one of severaldefensive formations, dependingon the size of the queue.

Queues of about 10 or fewerlobsters form a circle in whicheach lobster faces outward withits abdomen tucked and its long,sharp antennae held forward.When larger queues encounter apredator, the lead lobster slowsand begins to turn sharply. Thefollowers remain in contact asthe straight queue coils up. Theresult is a spiral called a rosette,

with the leader on the inside andthe last in line on the outer edge.Sometimes, a queue will sortitself into several rows of lob-sters aligned side by side, facingthe predator. This type of forma-tion, called a phalanx, is oftenformed when the lobsters canuse a rock or other structure forprotection from the rear.

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The Gregarious LobsterTeaching Strategies Tell students that the gregariousbehavior of the Caribbean spinylobster is advantageous in that itensures that each individual lobsteris a less likely target for predation.During migration, small initialqueues and individual lobsters jointogether to form longer lines of upto 65 lobsters. When the lobstersare not migrating they live in smallgroups and exhibit queuing behav-ior when leaving their dens at nightto forage for food.DiscussionWhat are some of the advantagesthe lobsters gain by formingqueues, rosettes and phalanxes?Drag is slightly reduced at the frontof the queue when the lobsters aretraveling in a line. The rosette andphalanx formations enable individuallobsters to become indistinguishablefrom one another when they form aclosely packed group. Predators mayhave difficulty selecting an individualtarget and may become confused.The appearance of a large group mayalso be intimidating to a predator.What are some types of predatorslobsters may encounter when theyare not sheltered? Spiny lobstersare preyed upon mostly by the trig-gerfish and the octopus.What are some other animals thatyou know of that exhibit migra-tory behavior and what is thepurpose of their migration?Students may mention birds andbutterflies that migrate to warmerclimates during the winter, salmonthat migrate to freshwater spawn-ing areas, and certain mammalsthat migrate in search of food.

TAKS 3 Bio 7B

Student Edition TAKS Obj 3 Bio 7B TEKS Bio 7B

Teacher Edition TAKS Obj 1 Bio/IPC 2C TAKS Obj 3 Bio 7B TEKS Bio 3D, 7BTEKS Bio/IPC 2C

pp. 832–833

TAKS 3

following familiar patterns in their everydayroutines. Some are painfully sensitive tosound, touch, sight, or smell. Children withautism do not follow the typical patterns ofchild development. In some children, hints offuture problems may be apparent from birth.In most cases, the problems become morenoticeable as the child slips farther behindother children the same age. With appropriatesupport, many people with autism can betrained to do meaningful work and partici-pate in the life of the community.

Demonstration Animal behaviorists (ethologists)are scientists who study how animals behave and the adaptivesignificance of behavior. These scientists consider all the possibleinfluences on animal behavior, suchas heredity, physiology, environ-ment, food, weather, and thebehavior of other animals. Invitean animal behaviorist to the classto speak. Ask the speaker toinclude the following in his or hertalk: recommended high schoolcourses, college degree needed,working conditions, employmentopportunities, and salary ranges.Have each student prepare severalquestions to ask the speaker. Havestudents write a short paperdescribing what they have learned.

Verbal

Group Activity Tracking Whales Teachers andstudents can track animal move-ments throughout the world on the Internet using WhaleNet. Thiseducational Web site providesupdated satellite data on bluewhales, harbor porpoises, and loggerhead turtles, as well asarchived satellite data on rightwhales, sperm whales, elephantseals, gray seals, harbor seals, andhooded seals. Another Web site ismaintained by the Sea TurtleSurvival League. Both sites showthe dates and tracking locations ofanimals on a world or regionalmap, which is updated periodically.Have students make maps and plotthe movements of individual ani-mals. Keep the maps on the wallfor other students to observe. Some of the transmitter batteriesfunction for only 2 to 3 months, soit is a good idea for your studentsto choose several animals to track.

Visual

TAKS 1 Bio/IPC 2C

Co-op LearningLS

Bio 3DLS

GENERAL


Isolated in worlds of their own, people withautism appear indifferent and remote and areunable to form emotional bonds with others.Although people with this baffling brain dis-order can display a wide range of symptomsand disabilities, many are incapable of under-standing other people's thoughts, feelings, andneeds. Often, language and intelligence fail to develop fully, making communication andsocial relationships difficult. Many peoplewith autism engage in repetitive activities, likerocking or banging their heads, or rigidly

REAL WORLDREAL WORLDCONNECTIONCONNECTION

CommunicationYou approach an unfamiliar dog and it begins to bark. You knowthat if you go closer, the dog might bite you, so you stop and talk toit. The dog continues to bark but not so aggressively, and it beginsto wag its tail. You and the dog have each responded to a signalgiven by the other.

A signal can be a sound, posture, movement, color, scent, orfacial expression. These signals are sent and received through all ofthe senses familiar to us—sight, hearing, smell, touch, and taste.Animals use signals to influence the behavior of other animals.Because they face a variety of social situations in which communi-cation is needed, animals usually have several different signals,each suited to a different situation, as shown in Figure 10.

Natural selection has shaped animal signals so that they reach theintended receiver efficiently and stimulate a response. To be trans-mitted efficiently, a signal must be able to travel through theenvironment from sender to receiver. A signal must also be recog-nizable to the receiver, or it won’t have any effect on behavior.Consider the loud mating call emitted by the male túngara frog. Thecall carries a long distance, reaching even far-off females. At night,when túngara frogs are active, a loud call is the best way tocommunicate. Visual signals, such as colors andmovements, would be noticeable from only a shortdistance away and would not be nearly as effectiveat attracting a mate.

Primate CommunicationAmong animals, vocal communication may be mostdeveloped in the primates. Some primates, such asthose shown in Figure 11, have a “vocabulary” ofcalls that allows individuals to communicate theidentity of specific predators, such as eagles, leop-ards, and snakes. Chimpanzees and gorillas can betaught by humans to recognize and use a large num-ber of symbols to communicate abstract concepts.Chimpanzees and gorillas cannot talk, however,because they are physically unable to produce the

Figure 10 Animalcommunication. A dog’s play bow means “I’m availableto play,” while a snarl is a signal of aggression andsometimes fear.

Figure 11 Primatecommunication. Vervetmonkeys have distinct callsthat identify different kinds of predators.

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Answer

Answers will vary dependingon the foreign language of theinterviewee. InterpersonalLS

TAKS 3 Bio 7B

Real Life GENERAL

ObservingTerritorialBehavior inCricketsSkills AcquiredObserving, collectingdata, organizing data,analyzing

Teacher’s NotesTell students to remain quietand as still as possible so thecrickets are not affected by anynoise or movements. Have stu-dents place the objects aroundthe crickets so the crickets areabout the same distance fromeach object.

Answers to Analysis1. Answers will vary depending

on the crickets’ behavior.2. Answers will vary depending

on the crickets’ behavior.3. Answers will vary. Students

should not attribute a sense ofpurpose to the crickets’actions.

4. Answers will vary. Hypothesesshould describe the adaptivevalue of each behavior.

MISCONCEPTION ALERT

Ability to Reason Students often believethat an animal understands why it behavesin a certain way. We don’t know what ani-mals are thinking when they engage in theirbehaviors. The scientific evidence that hasbeen collected, however, indicates that non-human animals don’t have the same kind of reasoning abilities that humans have.

StrategiesStrategiesINCLUSIONINCLUSION

Students may wish to study an animal thatlives in or around their home or school. Havestudents create a list of how and why ques-tions about the animal’s behavior that theywould like to understand. Have studentswrite their hypothetical answers and thenresearch to find scientific answers to theirquestions. The findings may be reported tothe class or written as a report.TAKS 1 Bio/IPC 2A, 2C, 2D

• Gifted and Talented • Attention DeficitDisorder

sounds of speech. Some researchers believe that chimpanzees cancombine symbols they have learned in meaningful ways. But chim-panzees cannot rearrange symbols to form a new sentence with adifferent meaning. That is a very complex task, which only humanscan perform.

In humans, language develops at a very early age. Infants begin tolearn language by trial-and-error during the “babbling baby” phaseof childhood, at about six months of age. At first, infants all over theworld babble the same consonant sounds, including sounds theyhave never heard. Soon, however, the infants pick out the soundsused by the people around them and repeat only those sounds. Theother sounds begin to drop away and are forgotten. Children quicklyand effortlessly learn a vocabulary of thousands of words, a feat nochimpanzee can do. This ability to learn language rapidly seems tobe genetically influenced. But language is not the only form ofhuman communication. Evidence suggests that odors and nonver-bal signals (body language) may also be important.

Real LifeJust say /r/. If you are having troublemastering the throatysound of a French /r/, justremember that a Frenchstudent struggles with theEnglish /th/ sound, and will probably pronouncethe as zee.Finding Information Interview a native speakerof a foreign language. Ask him or her to identifythree sounds in his or herlanguage that are difficultfor English speakers to master.

Observing TerritorialBehavior in CricketsThe chirp of a male cricket attracts femalesand warns other males to stay away fromhis territory. You can study chirping behav-ior by observing crickets in an aquarium.

Materials

5 male crickets, each marked with a differentcolor; 5 unmarked female crickets; coveredaquarium; slice of apple and of potato; smallplastic jar; 5 cm (2 in.) square of cardboard

Procedure

1. Place the crickets and food inan aquarium. Make two shel-ters by turning the plastic jaron its side and by folding thecardboard in half to form atent-like structure.

2. Make a chart like the oneabove to record the behaviorof the male crickets.

3. Observe the crickets for 10minutes. Among the males,look for territorial (aggressive)behaviors—chirping, strokingothers with antennae, push-ing others away, etc.

4. For each observation ofaggressive behavior, recordthe color of the aggressivemale and where the behavioroccurred—for example, nextto the jar or the tent.

5. For each cricket, tally thenumber of times aggressivebehavior was observed.Make a list that ranks eachcricket, placing the cricketwith the highest tally on top.

6. Then tally the numbers forwhere the behaviorsoccurred. Rank the locations.

Analysis

1. Critical ThinkingAnalyzing Data Were any crickets more aggressivethan the others? Giveevidence to support youranswer.

2. Describe the circumstancesin which most aggressivebehavior occurred.

3. Propose a reason to explainyour answer to item 2.

4. Critical Thinking Form-ing Hypotheses For eachaggressive behavior youobserved, form a hypothesisthat explains its function.

DATA TTABLE

Cricket Behavior

Cricket Apple Potato Jar Tent Female

Blue

Yellow

Red

Green

White

2B 2C 11B

7B

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TAKS 1

TAKS 1 Bio/IPC 2B, 2C; Bio 11B

Student Edition TAKS Obj 1 Bio/IPC 2B, 2C TAKS Obj 3 Bio 7B TEKS Bio 7B, 11BTEKS Bio/IPC 2B, 2C

Teacher Edition TAKS Obj 1 Bio/IPC 2B, 2C TAKS Obj 2 Bio 6DTAKS Obj 3 Bio 7A, 7B TEKS Bio 6D, 7B, 11BTEKS Bio/IPC 2A, 2B, 2C, 3C

pp. 834–835

Depression In the United States, the greatesthealth problem that affects behavior is depres-sion. It is known as “the common cold ofmental health problems.” Students should beaware that it is not unusual for a person to besaddened by divorce, the death of a loved one,or other major losses. But when the sadnessdoes not go away, it becomes what authoritiescall “clinical depression.” More than 15 mil-lion Americans suffer clinical depression at any given moment. The dark cloud of

depression has an even darker lining—suicide.Suicide is now a leading cause of death among teens and young adults. Fortunately,depression is highly treatable when diagnosedaccurately and attacked with some combina-tion of antidepressant medication and themany non-drug therapies. John McIntyre,M.D., a past president of the AmericanPsychiatric Association, says, “There is virtually no one who cannot be helped.”

Intrapersonal Bio/IPC 3CLS

Teaching TipAnthropomorphism Tell studentsthat attributing a human trait to anonhuman is known as anthropo-morphism. People often attributehuman emotions to animals. Forexample, someone might say that amother bird is sad because one ofher chicks fell out of the nest.While the female bird may engagein behavior that shows it under-stands and is concerned about thesituation, we can’t say that the birdfeels sadness as humans do.

Vocabulary The study of behav-ior is known as ethology, from theGreek word ethos, meaning “char-acter” or “custom.”

Discussion Tell students that twomechanisms are involved in sexualselection. The first is competitionbetween individuals of the samesex, usually males, for access tofemales. This form of selection hasresulted in the evolution ofweaponry such as antlers andhorns, and increases in male sizethat provide some individuals withan advantage over others for accessto females. The second mechanismis mate choice by individuals of theselecting sex, usually females. Thisform of selection has resulted inthe evolution of traits such as theshowy tail of the peacock, elabo-rate coloration in birds and fishesand many kinds of vocalizations.As with many other animals, sex-ual size dimorphism has evolved inhumans, probably due to male-male competition. Males generallyhave more developed musculaturethan females due to the effects oftestosterone at puberty. Lead theclass in a discussion of examples ofboth forms of sexual selection inanimals, including humans.TAKS 3 Bio 7A (grade 11 only), 7B; TAKS 2 Bio 6D (grade 10 only)

SKILLBUILDER

READINGREADING

BUILDERSKILL

TAKS 3 Bio 7B


Reproductive BehaviorWhen ready to mate, animals produce signals to communicate withpotential partners. Each species usually produces a uniquecourtship signal that ensures that individuals do not mate withindividuals of another species. For example, the flash patterns offireflies differ between species. A female firefly recognizes a male ofher own species by the pattern of his flashes, and she will ignoreany male that has a different flash pattern. The chemical producedby a female silk moth attracts only males of her own species. Manyspecies of insects, amphibians, and birds produce unique sounds orsongs to attract mates. A white-crowned sparrow will respond tothe song of another white-crowned sparrow, but it will totallyignore the song of an English sparrow.

During the breeding season, animals make several important“decisions” concerning mating and parenting. These include howmany mates to have and how much time and energy to devote torearing offspring. These decisions are all aspects of an animal’sreproductive strategy, a set of behaviors that have evolved and thatmaximize reproductive success.

Mate ChoiceMales and females usually differ in their reproductive strategies. Inmany animals, females do not mate with the first male theyencounter. Instead, the female seems to evaluate the male beforeshe decides whether to mate. This behavior, called mate choice, hasbeen observed in many invertebrate and vertebrate species. Femaletúngara frogs, for instance, have been observed “shopping around”among calling males. A female will sit neara male and listen to his call for severalminutes, then move on to another maleand listen to his call. She may evaluate sev-eral males before choosing one with whichto mate.

Sexual Selection What characteristics doanimals use in choosing a mate? WhenCharles Darwin considered this questionmore than a century ago, he made animportant discovery about evolution. Dar-win noticed that males often have extremecharacteristics that they use in theircourtship displays. Take, for example,widowbirds, shown in Figure 12. During thebreeding season, the male widowbird growsan extremely long tail, up to five timeslonger than the female’s. How did suchdifferences between the sexes evolve? Thelong tail of the male widowbird cannot beessential for survival, since the female birdsurvives quite well with a much shorter tail.

Figure 12 Widowbirds.During breeding season, thetail of the male widowbird,shown above, grows to morethan three times the length ofhis body. At other times of theyear, it is similar in length tothat of the female, which is the bird on the left in the inset photograph.

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ReteachingHave students go through this sec-tion and turn each subhead into aquestion on a sheet of paper. Thenask them to write an answer toeach question. Ask volunteers toshare their questions and answerswith the class.

Quiz1. What is the selective advantage

of territorial behavior? (It pre-serves natural resources for use byan individual or his group.)

2.Do animals that don’t vocalizeengage in communication?How? (Animals that don’t com-municate using vocalizations maycommunicate by posture, move-ment, color, scent, or facialexpression.)

3. In most animal species, whichsex chooses the mate? (female)

AlternativeAssessmentHave students review the types ofbehavior shown in Figure 9. Thenhave them locate every example ofanimal behavior mentioned in thechapter. If a behavior fits in one ofthe categories listed in the figure,have them place it there as anexample. (For example, defensivebehavior—musk oxen form a defen-sive circle around their young.) Ifstudents identify a behavior thatdoes not fit into a category, havethem make a new category for it.Students should justify the need forany category they create.TAKS 1 Bio/IPC 2C; TAKS 2 Bio 6D(grade 10 only); TAKS 3 Bio 7B

GENERAL

TAKS 3 Bio 7B; Bio 11B

GENERAL

only); TAKS 3 Bio 7B; Bio 11BTAKS 2 Bio 6D (grade 10

CloseClose

Answers to Section Review

1. parental care—ensures the survival of off-spring; courtship—attracts mate; defensive—predator protection; foraging—food location;migratory—movement to better environment;territorial—protects a resource

2. for example: sound—dog barking indicatingalarm; posture—person with hands on hipsindicating irritation; movement—threat displayindicating impending attack; color—brightplumage indicating quality of genes; scent—dogmarking territory; facial expression—frowningindicating displeasure

3. The most intimidating male (for example, thedeer with the largest antlers) has a better

TAKS 3 Bio 7B

TAKS 3 Bio 7B

chance of becoming the dominant male. Hewill mate with more females and pass on moreof his genes than subordinate males will.

4. A. Incorrect. The signal the maleproduces is visual, not olfactory. B. Correct.Male fireflies have species-specific flash pat-terns that the females recognize. C. Incorrect.The signal the male produces is visual, notauditory. D. Incorrect. The signal the male pro-duces involves flashes of light, not productionof a nest. Bio 11B

Bio 11B


Darwin recognized that extreme traits, such as the male widow-bird’s tail, could have evolved if they helped males attract or acquiremates. He proposed the mechanism of sexual selection to accountfor such traits. is selection in which a mate is cho-sen based on a certain trait or set of traits. Thus, traits that increasethe ability of individuals to attract or acquire mates appear withincreased frequency. Even traits that have a negative effect onsurvival can evolve in this way, provided that their benefits to repro-duction are high enough.

It is usually females that select mates based on their physicaltraits. One explanation for this tendency is that reproduction has agreater metabolic cost and requires a greater investment fromfemales. For example, eggs are less numerous and much largerthan sperm. (Humans’ eggs are about 195,000 times larger!) Inmammals, females are also responsible for gestation and milk pro-duction. Males may show mate choice as well if their parentalinvolvement is high. This happens in crickets, where the spermpacket a male deposits makes up 30 percent of his body weight,contributes nutrition for the female, and helps her develop eggs.

Competition by Males What kinds of traits help males acquiremates? Because male animals usually compete among themselvesfor the chance to mate with a female, selection has often favoredtraits that make males more intimidating or better at combat. Forexample, in many animal species, such as the gorillas shown inFigure 13, the male is much larger than the female, and the largestmale will have the most opportunities to mate. Other examples oftraits related to male competition are antlers in deer and moose,horns in bighorn sheep, and manes in lions. The extreme traits ofsome male animals, such as large size and tusks in walrus, oftenpermit males to assess each other. Males that are not physicallywell matched rarely engage in serious fights. Thus, some extremetraits may reduce conflict among males rather than increase it.

Competition among males can also take subtle forms. In somespecies, a male can gain a reproductive advantage over other malesby interfering with their reproduction. For instance, in somespecies of worms, butterflies, and snakes, the male seals thefemale’s reproductive tract after mating, thus preventing othermales from mating with her.

Sexual selection

Describe the function of six different animalbehaviors. 7B

Summarize in words and with examples theways in which animals use signals. 11B

Discuss how selection can account for theextreme traits found in the males of somespecies. 7B

A female firefly recognizesmales of her own species because the malesproduce a specific 11B

A chemicalB flash pattern C soundD type of nest


Section 2 Review

Figure 13 Gorillas. Onaverage, male gorillas are 50percent larger than females.Full grown males can weigh asmuch as 200 kg (440 lb).

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Student Edition TAKS Obj 2 Bio 6D TAKS Obj 3 Bio 7B TEKS Bio 6D, 7B, 11B

Teacher Edition TAKS Obj 1 Bio/IPC 2C TAKS Obj 2 Bio 6DTAKS Obj 3 Bio 7B TEKS Bio 6D, 7B, 11BTEKS Bio/IPC 2C

pp. 836–837

AlternativeAssessmentInsect societies, like those ofhumans, exhibit complex behavioralpatterns. Have students use libraryand online resources to obtain infor-mation about a behavioral pattern exhibited by a particularsocial insect. Have them prepare abrief written report and share theirfindings with the class.

Answer to Concept Map

The following is one of several possible answersto Performance Zone item 15.


can be

Behavior

stimulus

innate behavior learned behavior

conditioning reasoningfixed action pattern behavior

imprinting sexual selection

such as

such as such as such as

which requires a

• Science Skills Worksheet• Critical Thinking Worksheet• Test Prep Pretest• Chapter Test GENERAL

GENERAL

GENERAL

Chapter Resource File

Key Concepts

Study CHAPTER HIGHLIGHTS

ZONEKey Terms

Section 1behavior (824)innate behavior (826)fixed action pattern behavior (826)learning (827)conditioning (827)reasoning (828)imprinting (829)

Section 2sexual selection (836)

Evolution of Behavior

● A behavior is an action or a series of actions performed inresponse to a stimulus.

● Natural selection favors behavioral traits that increase thelikelihood of an individual’s survival and reproduction.

● Genetically programmed behaviors are called innate behav-iors, instincts, or fixed action pattern behaviors, and thereis little or no variation in how they are performed.

● Learning is the modification of behavior by experience.Learning may occur by association with an unrelated stimulus(classical conditioning) or by trial-and-error (one type ofwhich is operant conditioning).

● Reasoning is the ability to think of a possible solution to aproblem.

● Many behaviors, especially complex behaviors, have bothgenetic and learned aspects.

● Learning determines the final shape of many geneticallybased behaviors, such as imprinting.

Types of Behavior

● Animal behaviors fall into several broad categories, which include parental care, courtship behavior, defensivebehavior, foraging behavior, migratory behavior, andterritorial behavior.

● Most animals use signals, often vocal or visual, tocommunicate with one another.

● Primates are unique among animals in using symbols tocommunicate.

● The human ability to learn language rapidly during child-hood seems to be genetically influenced.

● By the mechanism of sexual selection, traits that increasethe ability of an individual to attract a mate appear withincreased frequency.

2

1

837

ANSWERS

Using Key Terms

1. c2. b3. a4. c5. a. “How” questions are about

how a behavior is triggered,controlled, and performed.“Why” questions concern theadaptive value of a behavior.

b. Innate behavior is geneticallyprogrammed, whereas learnedbehavior comes fromexperience.

c. In classical conditioning, twounrelated stimuli are paired,and the response to onebecomes associated with theother. In operant conditioning,an apparently randomresponse is linked with a stim-ulus if the response is rewardedor punished repeatedly.

Understanding Key Ideas

6. c7. c8. c9. a

10. d11. d12. c13. Satellite tracking saves the

expense and time researchersmust spend to follow an animalthat has a radio collar. The radiocollar also has a limited range,and the animal can travel to areasthat are inaccessible to people.TAKS 3 Bio 7B; Bio 11B

TAKS 3 Bio 7B

TAKS 3 Bio 7B; Bio 11BTAKS 3 Bio 7B; Bio 11BBio 11BTAKS 3 Bio 7B; Bio 11BTAKS 3 Bio 7B

TAKS 3 Bio 7BTAKS 3 Bio 7BTAKS 3 Bio 7BTAKS 3 Bio 7B

14. In natural selection, traits that help an animalsurvive to reproductive age tend to be passedon to the next generation. Harmful traits willbe selected against. Like physical traits, manybehaviors are important for survival andreproduction. For example, it is just as impor-tant to survival for an animal to locate,obtain, and consume food (foraging behavior)as it is for it to be able to run swiftly frompredators. Animals that are poor at foragingmay not live to reproduce.

15. One possible answer to the concept map isfound at the bottom of the Study Zone page.TAKS 1 Bio/IPC 2C; Bio 3E

TAKS 3 Bio 7B

Section Questions1 1, 2, 3, 4, 5, 6, 7, 8, 14, 15, 16, 17,

20, 21, 222 9, 10, 11, 12, 13, 15, 18, 19

Assignment Guide


CHAPTER 36Performance

ZONECHAPTER REVIEW

Using Key Terms1. The orb spider builds her web in exactly

the same way every time. This is an example of 7Ba. abnormal behavior.b. learned behavior.c. fixed action pattern behavior.d. random behavior.

2. Learning by association is called 7Ba. reasoning.b. conditioning.c. imprinting.d. assuming.

3. The ability to analyze a problem and thinkof a possible solution is called 7Ba. reasoning.b. conditioning.c. imprinting.d. assuming.

4. Learning that can only occur during aspecific period early in an animal’s life is called 7Ba. reasoning.b. conditioning.c. imprinting.d. assuming.

5. For each pair of terms, explain thedifferences in their meanings.a. “how” questions, “why” questionsb. innate behavior, learned behaviorc. classical conditioning, operant

conditioning

Understanding Key Ideas6. A male lion that takes over a pride may kill

all the young cubs in order to ensure thesurvival and reproduction of 7Ba. the females. c. himself.b. the pride. d. his siblings.

7. The nest-building behavior of Fischer’slovebirds is 7B 11Ba. learned.b. a result of operant conditioning.c. innate.d. gradually learned.

8. Which of the following best representsclassical conditioning? 11Ba. the feeding behavior shown by rats in

Skinner boxesb. a male túngara frog calling to a femalec. a dog salivating at the sound of a belld. a primate giving a warning signal to

members of its troop

9. Parental care is performed in order to a. ensure survival of young.b. protect parents from predators.c. protect a resource for exclusive use.d. locate, obtain, and consume food.

10. The purpose of foraging behavior is toa. ensure survival of young.b. protect individuals from predators.c. protect a resource for exclusive use.d. locate, obtain, and consume food.

11. Which of the following behaviors is leastlikely to be associated with food resources? a. territorial c. foragingb. migratory d. defensive

12. Which of the following best demonstratesthe mechanism of sexual selection? 7Ba. a female túngara frog listening carefully

to the call of a potential mateb. the flash pattern found in firefliesc. the long tail of a male widowbirdd. the killing of cubs by male lions

13. What advantages does trav-eling in a queue provide to spiny lobsterduring mass migration? 7B 11B

14. Summarize the mechanism of naturalselection, and explain why behaviors arejust as important to survival and reproduc-tion as physical features are. (Hint: SeeChapter 13, Section 1.) 7B

15. Concept Mapping Construct aconcept map describing animal behavior.Use the following terms in your map:behavior, stimulus, innate behavior, fixedaction pattern behavior, learned behavior,conditioning, reasoning, imprinting, andsexual selection. 2C 3E

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Review and AssessTAKS Obj 1 Bio/IPC 2CTAKS Obj 3 Bio 7BTEKS Bio 3E, 7B, 11BTEKS Bio/IPC 2C

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Critical Thinking

16. Answers may vary. It is valid. Theducks have become conditioned toapproach when a human nears thepond; humans are conditioned tofeed the ducks when ducks swimover to them.

17. Answers may vary. The flaw in thisargument is that the variable oflearning (“nurture”) has not beeneliminated.

18. Answers may vary. Capture andhandling may have affected thebehavior of the widowbirds. Thescientist should include a controlgroup of captured and manipulatedmales whose tails are not cut off orare cut off and then reattached.

19. Answers may vary. In some birdspecies, females prefer males thatare more brightly colored orextravagantly plumed. Since thefemale chooses her mate, maleswith these traits are more likely tobe chosen. As a result, these traitsappear with greater frequency inthe male population.

Alternative Assessment

20. Answers will vary. All students in the group should make a significant contribution to thepresentation.

21. Answers will vary. Several ideasmay explain the “how” of thisphenomenon. For example, thewhales may follow prey into shal-low waters. One possible “why”answer is that whales that do this(without becoming stranded) aremore likely to find enough foodto survive and reproduce.

22. Answers will vary. Trainers of dis-abled persons’ service animals areknowledgeable about animalbehavior and the needs of disabledpersons. They condition animals torespond to human voice, contact,and to commands. Animal trainersneed at least a high school diplomaor GED equivalent, and most needa bachelor’s degree and additionalskills. Certification is not manda-tory, but several organizations offertraining programs and certification.Most animal trainers are self-employed. Employment of animaltrainers is expected to grow.Starting salary will vary by region.



TAKS 3 Bio 7B



Bio 11B

1. A. Incorrect. The behavior is not an aggressivebehavior. B. Incorrect. The behavior is not asubmissive or aggressive behavior. C. Correct.The behavior is a “play bow,” which is an invi-tation to play. D. Incorrect. Foraging behavioris elicited by hunger.

2. F. Incorrect. The behavior is not a foragingbehavior. G. Correct. The behavior is imprint-ing, which is how goslings learn to recognizeand follow their mothers. H. Incorrect.Traveling in single file will not necessarily deter

Bio 11B

predators. J. Incorrect. Associating withhuman does not enhance reproductive successin geese.

3. A. Incorrect. Natural selection favors behaviorswith adaptive value. B. Incorrect. All young ina group may not be protected. C. Incorrect.Natural selection does not favor the death ofall young because the species would becomeextinct. D. Correct. The male lion kills off-spring that are not his own and allows his ownto survive. TAKS 3 Bio 7B; Bio 11B

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Test

Use the photos below and your knowledge ofscience to answer questions 1–3.

1. How is another dog likely to respond to thesignal given by the dog in A?A by cowering in fear C by playing B by attacking D by foraging

2. Why might natural selection favored theevolution of the behavior shown in B? F Goslings that can recognize the shape of

a bucket are more likely to find food.G Goslings that follow their mother are

more likely to find food and avoid danger. H Adult geese that travel in single file as a

group are more likely to avoid predators.J Adult geese that associate with humans

are more likely to reproduce.

3. The behavior shown by the adult lion in Cmay have evolved because natural selectionfavors behaviors that A have no adaptive value.B protects all young in a group.C lead to the death of all young in a group.D help more of one’s own offspring to

survive.

A

C

B


Always read the question before looking at theanswer choices.

Critical Thinking Skills16. Evaluating Conclusions Evaluate the valid-

ity of the following statement, “Humanswho feed ducks at a pond are just as condi-tioned to this behavior as are the ducks thatcome to feed.”

17. Evaluating an Argument “A child’s behav-ior closely resembles the behavior of itsparents. Therefore, most human behaviorsare genetically controlled.” Explain thelogical flaw in this argument.

18. Critiquing a Scientific Explanation Malewidowbirds whose tails have been cut, matewith half as many females as males withlonger tails. Should a scientist conclude thatfemale widowbirds prefer males with longertails? Why or why not?

19. Recognizing Relationships In many birdspecies, the male is more brightly coloredand heavily plumed than the female.Explain this in terms of sexual selection and evolution.

Alternative Assessment20. Finding and Communicating Information

Use the media center or Internet resourcesto learn more about imprinting. Work witha small group to find examples of imprint-ing, and develop a class presentation onthe subject.

21. Summarizing Information At times, somespecies of whales seem to deliberately swiminto waters that are shallow. Often they endup stranded on the beach, where they can-not survive. Using the Internet or otherresources, search for information you canuse to answer the “how” and “why” ques-tions about this phenomenon. Present yourfindings in a report to your class.

22. Career Focus Animal Trainer Research thefield of training service animals for disabledpeople, and write a report on your findings.Your report should include a job descrip-tion, training required, kinds of employers,growth prospects, and salary ranges.

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Documents

Section 1 Evolution of Behavior - Jourdanton ISD · • Lesson Plan • Directed Reading ... in response to a stimulus. ... no variation in what she does,